Glossary

[A]
 
  Acquired Images
Images sent from your scanner software to the host graphics application.
 
Adobe RGB
Color profile (color space) advocated by Adobe Systems Inc. Color profiles (color spaces) are a determination of the range of colors that can be reproduced on or in such things as computer screens or standard printed publications.
The sRGB color profile (color space) is normally used. Adobe RGB, however, offers a wider color range. Compatibility with Adobe software is good and saving image files in Adobe RGB will produce results that are closer to the actual image. It can be used with the Save button or Scan-1/2 buttons in CanoScan Toolbox.
 
Auto Color/Auto Tone
A function that analyzes an image automatically and balances the highlights and shadows.
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[B]
 
  Backlight Correction
This function corrects films and images that have been shot with reverse lighting by brightening the dark portions and darkening the bright portions of the image.
 
Bit, Bit Count
An indication of the volume of data used to describe points in an image. A 1-bit image assigns image data black or white color values depending on whether the brightness value is above or below a particular threshold value. The result is a two-color image. An 8-bit grayscale image expresses an image in 256 shades of gray ranging from white to black. A 24-bit color image assigns 8 bits to each RGB color channel, expressing each pixel in approximately 16.8 million colors.
 
Black-Point
The darkest point in an image that has been scanned as a color or grayscale image. The Black-Point Eyedropper can be used to click on an image and set all the data darker than the sampled color to black. See also Mid-Point Eyedropper, White-Point Eyedropper.
 
Black-Point Eyedropper
A tool on the Histogram window that allows you to select the color you wish to set to the black-point in the preview area.
 
Borderless Printing
A setting used to print a scanned image. If a check mark is placed beside this category, the image is printed without a border over the entire page. This setting is only available with Canon Bubble Jet printers that support borderless printing.
 
Brightness
The luminosity value of data when it is scanned. Raising the brightness setting makes the overall image brighter, while lowering it makes it darker.
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[C]
 
  Calibration
A scanner function that automatically recalibrates the scanner so that it uses true white as the basis for generating all other colors accurately.
 
Color
An image type that expresses images using 256 colors (8 bits) for each red, green and blue channel, resulting in an approximate total of 16.8 million colors (256 x 256 x 256) per pixel in the image.
 
Color Balance
The balance of colors in a color image. An image's color balance can be adjusted by slightly adjusting the mix of red, green and blue, or cyan, magenta and yellow.
 
Color Channels
The red, green, or blue components of a color image. Color images contain 8 bits per pixel each for red, green, and blue channels, therefore each pixel has 24 bits. If you are scanning a color image, you can change the brightness and contrast of the individual red, green, and blue tones in your image. The Master channel is a combination of the three. If you select the Color (48 bit) option for the Color mode in ScanGear CS in the Advanced mode, each pixel is assigned 16 bits per color channel for a total of 48 bits per pixel in the master channel.
 
Color Matching
In some cases, the range of colors captured by a scanner exceeds the range that can be displayed by a particular monitor. In addition, the colors displayed for an image on the monitor may be slightly different than those output by a printer. Color matching is the process used to make the colors captured by a scanner consistent with those shown on a display or printed on a printer.
 
Color Mode

Sets the mode in which images are scanned and processed.
There are basically three modes: Black and White, Grayscale and Color.

Black and White Expresses images in white and black only. Each pixel is expressed with a single bit of data.
Grayscale Expresses images in shades of gray ranging from white to black. At the 8-bit setting, each pixel can be expressed in one of 256 shades, and at the 16-bit setting, in 65,536 shades.
Color Expresses images in color. Images are composed of groupings of 3 dots (pixels) in the three primary colors (Red, Green and Blue). The number of shades available for each pixel is same as for the grayscale modes. At the 8-bit setting, three pixels multiplied by 8 bits yields what is called 24 Bit Color, and at the 16-bit setting, three pixels multiplied by 16 bits yields 48 Bit Color, or 16.7 million possible shades and 280 trillion possible shades, respectively, for expressing each pixel.

The available color mode settings will depend upon your scanner model and the software in use, as well as the selected processing settings, such as "Descreen" and "Auto crop." ScanGear CS and CanoScan Toolbox make it possible to combine these settings with the color modes to select the options best suited to the type of item being scanned and the intended use of the scanned image.

Example of ScanGear CS Color Mode Settings (Varies between scanner models)

Black and White Select this mode when outputting photos and other items to a monochrome printer. It expresses images in two colors, black and white. It uses a particular threshold value at which image data is either expressed as black or white, according to the brightness level. The threshold value can be adjusted.
Grayscale Select this mode to scan black and white photos or monochrome images. It expresses images in 254 shades of gray (grayscale) and black and white, making a total of 256 shades.
Grayscale (16bit) Select this mode to scan black and white photos or monochrome images. It expresses images in 65534 shades of gray (grayscale) and black and white, making a total of 65536 shades. This mode can only be used to scan film.
Color (photo) Select this mode to scan color photos. It expresses images in 256 colors (8 bits) for each R(ed), G(reen) and B(lue) color channel.
Color (Documents) Select this mode to scan color documents that include text or charts in addition to color photos. It expresses images in 256 colors (8 bits) for each R(ed), G(reen) and B(lue) color channel.
Color (48bit) Select this mode to scan color photos in greater detail. It expresses images in 65,536 colors (16 bits) for each R(ed), G(reen) and B(lue) color channel.
Text Enhanced Select this mode to scan text more crisply, particularly to process it in an OCR program. It expresses images in two colors only, black and white.
This mode is not available in the Macintosh version.

In CanoScan Toolbox, it is referred to as the "Scan Mode." See the "Scan Mode" entry in the Glossary for an example of the CanoScan Toolbox Scan modes.
 
Contrast
The degree of difference between light and dark when an item is scanned. Raising the contrast in an image makes it appear sharper overall, while lowering makes it appear softer.
 
Create Multiple PDF
A category used when saving a scanned item as a PDF file using the PDF button in CanoScan Toolbox. If a check mark is placed beside Create multiple PDF, more than one item can be scanned and saved in a single PDF file.
 
Create Searchable PDF

A setting used to save a scanned image as a PDF format file. If a check mark is placed beside this option, the program recognizes the text in a document. Simple keyword searches can then be performed on the saved PDF file.
 
Crop
The action of selecting only part of an image for use. Using the Crop button on the ScanGear CS Toolbar, a portion of the preview image can be selected and only that portion is then re-previewed or included in the final scan.
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[D]
 
  Descreen
A function that reduces the occurrence of moiré in the scan of a printed item. Moiré is the patterns or stripes that are visible in a low-resolution scan of a picture or photo in a book or magazine due to the interference patterns between the dots that comprise the image.
 
Dot
Images are reproduced as rows and columns of dots. When an item is scanned with a scanner, the resolution, or dot density, of the scanned image is measured as the number of dots per inch (dpi).
 
dpi
An acronym for dots per inch. The resolution of a monitor or printer is expressed as the number of dots per horizontal inch that it can display or print, respectively. See also Pixel, Input Resolution, Resolution.
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[E]
 
  Easy Color Matching
A function which coordinates colors between the scanner and a printer with easy operation. This function is supported in CanoScan Toolbox's Print function.
 
Eyedropper
A tool in the Histogram window used to sample a black-point, mid-point or white-point color in a preview image.
 
Exif File
An image file format primarily used by digital cameras. It is compatible with the direct print function. CanoScan Toolbox can create files in this format.
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[F]
 
  Fading Correction
This function corrects the color and scans films that have faded due to the passage of time or other causes and photos or films with indistinct colors.
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[G]
 
  Gamma, Gamma Curve
A setting that adjusts brightness so that the brightness of the original item, the input data, is consistent with the brightness expressed in the display (the output data) or in print output. The input/output relationship is expressed with the gamma value, where 1 is the base value, and anything less than 1 changes the output to a darker setting and anything over 1 makes it brighter. The curve that expresses this relationship in a graph, and can be used to adjust it, is called the gamma curve or tone curve.
 
Grain Correction
This function reduces the granular appearance of high-sensitivity films, pushed films and images created from such films as well as films that are scanned at high resolutions.
 
Grayscale
An image type that scans only the brightness data from an image and expresses the results in 256 shades (8 bits) of gray, ranging from pure white to pure black.
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[H]
 
  Histogram
A graph that shows the distribution of brightness data in an image. An image is a collection of data that is assigned varying brightness values. The brightness levels are expressed as a range of values from 0 (shadows) to 255 (highlights). The assignment of brightness levels can be changed with the Histogram function in ScanGear CS.
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[I]
 
  Image File
A set of data possessing color and brightness characteristics that are used to express an image and are converted into a format that can be handled by a computer.
 
Image Quality
A setting used to scan images. It is the resolution at which an item is scanned, and is measured in dots per inch (dpi). The larger the value, the finer the scanned image becomes. See Resolution, dpi.
 
Input Resolution
The resolution at which a scanner can capture data with its optical equipment without further digital processing. It is measured as the number of dots per inch (dpi) it can scan. The input resolution of scanners varies with the scanner type. See also dpi, Resolution.
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[M]
 
  MAPI
A specification for exchanging messages through e-mail and other means between computers. If software with this function is loaded, then MAPI-compliant application programs can send e-mail without themselves possessing specific transmission coding.
 
Mid-Point
The center point between the shadow and highlight ranges in an image.
 
Mid-Point Eyedropper
A tool in the Histogram window that selects the mid-point value for the preview image. When the Mid-Point Eyedropper is clicked on the image, all the color values of the data between the black-point and white-point are adjusted to the sampled mid-point value.
 
Multi-Scan, Multi-Crop
Functions that scan multiple items on the document glass of the scanner in the corresponding number of individual image files in a single operation. If an item is placed slightly out of alignment on the document glass of the scanner (up to a 10degree tilt), its orientation is automatically corrected.
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[O]
 
  OCR
Optical character recognition (OCR) programs convert text images into actual text characters editable by word-processing programs and others. If the [Text Enhanced] function (Windows only) is selected as the color mode in ScanGear CS, the image is scanned with high black/white contrast, making it easier for the OCR program to correctly recognize text.
 
OCR Program
An OCR program is one that converts text images into editable text characters.
 
Output Resolution
A setting used to set the fineness or resolution at which an item is reproduced. It is measured in units of dots per inch (dpi). The larger the value, the finer the image.
See also dpi, Resolution.
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[P]
 
  PDF

An acronym for Portable Document Format. A file format that can be displayed and printed with Adobe Acrobat Reader / Adobe Reader.
CanoScan Toolbox can save the scanned image as a PDF file, it can also recognize characters. The saved PDF file is utilized for simple keyword search or such.

 
Pixel
Short for picture element, a pixel is the smallest unit used to measure a display image.
 
Preview
A low-resolution scan of an item that is displayed in the Preview Area. The preview image can be used to check the image, select or crop portions of the image, adjust contrast and brightness, and apply various filters.
 
Preview Area
The area at the left of the ScanGear CS main window. When the Preview button is clicked, the item(s) on the document glass of the scanner are scanned, and the results are displayed as the preview image in this area. At this stage, the scanned image is not passed on to the host application program.
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[R]
 
  Reduce Dust and Scratches
A filter that reduces "noise" in images caused by dust and scratches on color photos when they are scanned.
 
Remove Dust and Scratches
A function that automatically compensates for small pieces of dust or scratches on film when it is scanned.
 
Resolution
Term used to represent the density of the collection of dots with which an image is expressed.
 
RGB
An acronym for the three primary colors of light-red green and blue. The scanner detects the light reflected off the item being scanned with its red, green and blue sensors. Printers, on the other hand, use a complementary color set to RGB: cyan, magenta, yellow and black (CMYK). Cyan, magenta and yellow are referred as the 3 primary colors of color.
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[S]
 
  Scan Mode
A setting used to scan images. The following scan modes are available in CanoScan Toolbox.
* Black and White
Scans items as black and white images with only those two colors.
* Grayscale
Scans items as achromatic images (similar to monochrome pictures) using
black, white and shades of gray.
* Color
Scans items as color images with the Descreen function set to Off. See
Descreen.
* Color (Magazine)
Scans items as color images with the Descreen function set to On. See Descreen.
* Color (Multi-Scan)
Scans items as color images. If more than one item is placed on the document glass of the scanner, each item is automatically scanned individually, straightened and placed in an individual image file.
* Color (Auto crop)
Scans items as color images. Automatically detects item positions and scans to fit all of the items in the smallest possible area.
 
Scanner Driver
A software program that controls how the computer operates the scanner. If the "Display the Scanner Driver" option is selected in CanoScan Toolbox, ScanGear CS will start and you can set the settings in detail.
 
Slider
A part of the Color Correction windows used to control and adjust settings. Drag the slider left or right to change a setting.
 
Status Area
The information area in the lower portion of the ScanGear CS main window. It displays the preview image's resolution, image dimensions, file size and other data.
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[T]
 
  Test Scanner Button
If the Test Scanner button in the Scanner tab of the Preferences dialog is clicked, the Scanner Diagnostics window opens and you can initiate a diagnostic test of the scanner. The report tells you if anything is wrong with the scanner.
 
Text Box
A box into which text can be input and printed along with a scanned image. Add text boxes in CanoScan Toolbox's Print Layout window, the dialog opened when scanning items using the Print button. Up to 10 text boxes can be placed anywhere on the page on which an image is printed. Font attributes, such as the font type, size and color, can be set for text entered into a box.
 
Threshold
The brightness value at which data in an image is either set to black or white when the image is scanned as a black and white image. The higher the threshold value, the darker the image. The lower the threshold value, the brighter the image.
 
Thumbnail Display

A mode for displaying a preview image of film scanned with ScanGear CS. The frame of film selected in the Film Guide is cropped and shown as a preview image. The alternate mode, Thumbnail Display Off, shows the periphery of the frame as well. Use the Thumbnail button on the Toolbar to switch between these two display modes.

 
Tone Curve
See Gamma, Gamma Curve.
 
Toolbar
A set of buttons on a bar at the top of the ScanGear CS Preview Area. Each button controls certain commands, such as selecting, rotating or inverting.
 
TWAIN
TWAIN is an industry standard for transferring information from scanners and digital cameras to computers. One interpretation of the acronym is "Technology Without An Interesting Name." TWAIN is an application programming interface (API) for image scanners and other input devices that allows different makes and models to be compatible as long as both the devices and application programs are TWAIN-compliant. For example, if you use a TWAIN-compliant image editing program and summon ScanGear CS for Windows, a TWAIN-compliant scanner driver, from within that program's menu, the scanned image can be passed directly to the editing program.
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[U]
 
  Unsharp Mask
A filter that emphasizes the outlines of objects within an image. It sharpens the appearance of an image without changing the brightness, contrast or color balance.
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[V]
 
  Vivid Photo
A function that analyzes the optimal colors for each photo and uses a proprietary method to color correct to achieve a broad range of color expression, including highly saturated cyans and greens. When this function is selected for printing, the blues of the sky or ocean and the full range of greens, including those of new growth, can be reproduced with a freshness and richness never before available. It does this without compromising other colors, such as skin tones. It judges with great precision which colors require correction and prints the others as they occur naturally. Thus, the Vivid Photo function can be used to reproduce any image with optimal color correction.
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[W]
 
  White-Point
The lightest point in an image that has been scanned as a color or grayscale image.
 
White-Point Eyedropper
A tool on the Histogram window that allows you to select the color you wish to set as the white-point in the preview area. The White-Point Eyedropper can be used to click on an image and set all the data brighter than the sampled color to white. See also Mid-Point Eyedropper, Black-Point Eyedropper.
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[Z]
 
  Zoom
The magnification of the Preview Area in ScanGear CS or part or all of an image in an application program window.
 
Zoomed Preview
A portion of an image rescanned and magnified in the preview area. Make a selection on an image and click the Zoom button to generate the zoomed preview image. This function re-previews the selected portion of the image at the largest resolution setting permitted by the display, enhancing the image quality of the preview image.
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